Sir John Doyle, 1st Baronet

Doyle transferred to the 40th (2nd Somersetshire) Regiment of Foot on its being ordered overseas, where he served with distinction in the American War of Independence (1775–1783). Serving as lieutenant of light cavalry at Boston he became Adjutant to the battalion. He was involved in the Battle of Long Island in August 1776, where he recovered the body of his commanding officer, Lieutenant-Colonel James Grant, under enemy fire.[7]^:5 He then fought at the Battle of Harlem Heights, In 1777 he fought at the Battle of Brandywine and Battle of Germantown (where he was wounded).[7]^:6

His wound changed the course of his American campaign because he was appointed to assist Lord Rawdon (Francis Rawdon-Hastings, 1st Marquess of Hastings) to raise the Volunteers of Ireland regiment (also known as 2nd American Regiment and which would shortly become a regular unit, the 105th Regiment of Foot), and wherein he was promoted to Captain. This unit then fought at the Battle of Monmouth Courthouse in 1778, and now appointed and acting Major of Brigade moved with the Regiment to South Carolina participating in the Siege of Charleston in 1780,[1] before being mentioned in dispatches after fighting at the Battle of Camden.[7]^:7 He also fought at the Battle of Springfield.

Following the peace in America in 1782 Captain Doyle returned to Ireland, entering politics.

Following France declaring war on Great Britain, in September 1793, Doyle raised his own regiment, the 87th (The Prince of Wales's Irish) Regiment;[7]^:16 they were also known as The Prince of Wales Irish Heroes.[1]

Raised in rank to brevet Colonel, he led the unit under the Duke of York in the Flanders Campaign 1793–1795. He served at the siege of Valenciennes 13 June-28 July 1793 and distinguished himself at Alost during Moira's retreat 1794 where he was wounded in a cavalry action, needing to return to Britain to recover. His Regiment, sent in his absence, to Bergen op Zoom where the Catholic town promptly surrendered to the French, making the whole Regiment prisoners of war.[7]^:18–9

Returning to Ireland he was appointed head of the war department and from 1796 until 1799 as Secretary of War. The release of his Regiment as prisoners saw Doyle appointed Colonel of the 87th Foot on 3 May 1796.

Appointed a brevet Brigadier-General he was appointed in charge of the land forces in the proposed assault on the Texel in October 1796 with the hope of destroying the Dutch fleet, however storms resulted in the ships abandoning the attempt.[7]^:21 Brigadier General Doyle was then ordered to Gibraltar, however on his way to the port of embarkation was attacked by highwaymen and badly wounded twice. Having recovered, he proceeded to join the staff in Gibraltar.[7]^:21–2

Confirmed in the rank of Brigadier General and appointed to command the 4th brigade, he served under Abercromby and Hutchinson in Egypt in 1801, and saw action at Manresa, Marabout, and Ramanieh 9 May. On 17 May 1801, in the Egyptian desert he led the 250 troopers of the 12th Light Dragoons to capture the 600 man, 460 camel French Dromedary Regiment (French: Régiment de Dromadaires) by persuading them to surrender without a fight.[7]^:23–6 The surrender of Cairo, concluding with the Alexandria in September. He distinguished himself during these operations leading to promotion to Major-General on 29 April 1802.[1][2]

He was appointed Lieutenant Governor of Guernsey in 1803. After declaring a "state of emergency" in 1804,[8] he undertook to improve the dilapidated defences and to improve upon them by building over 60 additional gun batteries at likely landing points. Costing considerable sums of money, he managed to persuade, through eloquence, the Island to pay for these costs, as the Islands were in imminent danger of invasion from France.[7]^:33

Doyle actively organised the defence in the Bailiwick of Guernsey, he oversaw the draining of land at Braye du Valle to connect the tidal north of the island to the main island, using the proceeds of the sale of the land to pay for the construction of military quality roads.[7]^:39–40 He organised three Martello towers to be built, including Fort Grey, to supplement the existing Guernsey loophole towers, progressing and completing Fort George. Working closely with the Royal Guernsey Militia and bringing to the island ordnance and regular infantry. In addition he improved, in a like manner, the defences of Alderney.[7]^:38